Waterproof abrasive fabric



Patented May, 17, 1927.

FRANK JOSEPH CRUPI, or BROOKLYN, NEW YORK, ASSIGNOR TO HER AN BEHR &

00., me, or BROOKLYN, NEW Years, A CORPORATION or NEW YORK.

WATERPROOF ABRASIVE FABRIC.

No Drawing. Original application filed February 19, 1924, Serial No. 693,903.- Divided and this application filed August 25, 1926. Serial No. 131,588.

This invention relates to and has for its object the production of a waterproof sandpaper or abrasive-fabric capable of withstanding disintegration when used on wet surfaces. I

According to the present invention I pro- I vide a coating, the fundamental element of Which is a cellulosic material (cellulose nitrate, cellulose acetate, or the like) as distinguished from oils, varnishes or resins. The cellulosic material is soluble in a variety of easily vaporizable solvents or mixtures 'of solvents and such a solution possesses the characteristics. necessary for handling and application. I 1

The principles of this invention may be applied in connection with a large variety of formulae. The relative amounts of cellulose nitrate, for example, and of its solvent, will obviously vary according to the consistency desired for every particular op; eration. One formula suitable for use in the production of the sand-paper of this invention, especially appropriate with relation to admixture with other material to be hereinafter referred to, is as follows: 16 ounces of cellulose nitrate (11 to 13% nitrogen) dissolved in one gallon of a solvent consisting of amyl acetate, 10% ace- {101118, 15% benzol and 15% denatured alco- The cellulosic material of the foregoing solution is the basis present invention and supplies the means by which the abrasive grains are retained on the base paper or backing material with suflicient tenacity to resist separation of the abrasive grains from the backing when the sand-paper is used in association with water. In connectlon withthe cellulosic solution I prefer to use one or more supplemental solutions, examples .of which may be stated as follows:

I. 50% of gum resins (25% copal25% sandarac), 50% denatured alcohol.

II. 4 pints of rape seed oil, 5 pints of ethyl acetate.

When mixed in the proportion of two gallons of the cellulosic solution, one gallon of solution I, and one gallon of solution II, a composition will be formed which can be applied with satisfactory results to the base material of the abrasivefabric, The result of the coating of the of using a solution such as No. to act as a spreader or filler material with respect to the ccllulosic material but to increase the hardness and adhesivencss of the coating while the result of using solution N 0. I1 is to act as an emollient, i. e. to produce or to increase a condition of flexibility. Neither the resins of solution I, nor the oil of solution II, however, are the active agents which retain the abrasive grains on the paper, that function being exercised by the cellulosic material of the cellulosic solution.

The cellulose nitrate may be of any per cent nitrogen composition and other solvents or combinations or proportions of solvents may be employed in place of the specific solvents and proportions recited in the forinula for the cellulosic solution above given. A result which is satisfactory for many purposes may also be obtained by using a composition of celluloid dissolved in a conven-' ient solvent or mixture of solvents, celluloid being cellulose nitrate treated with camphor, which is ordinarily termed a gum. Such a celluloid solution can be used either alone or in admixture with added camphor or camphor substitutes or gum resins may be added to increase or to accentuate hardness and ad hesive qualities. Compounds of cellulose acetate may also be employed in place of cellulose nitrate with equally satisfactory results. I

The process of manufacturing sand-paper in accordance with this invention consists of coating a fabrimbacking' with the described composition depositing abrasive grains upon this coating while in a plastic condition and drying by evaporating the solvent. After the first coating which carries the abrasive grains has dried, the sand-paper is given a top coating of the same composition and the paper is then thoroughly dried, which coinpletes its manufacture. The coating of this I is not only invention dries readily and with convenient speedand does not require the use of elaborate or special apparatus. The manufacture of sand-paper in accordance with the new process can be handled with the present equipment available at any sand-paper factory and does not require any excessive space for dry rooms, handling or other details of operation.

In most industries in which waterproof either be ore or after the other side of the sheet is coated with abrasive. It is prefer- 7 base or whether used in one or more coats able, however, to coat the back of the fabric with the same com osition which is, used in waterproofing the ace of the fabric.

Sand-paper produced in accordance with this invention is stable and does not deteriorate with the passage of time as is likely to occur in sand-paper in which the adhesive character of the coating is made to depend upon oxidation products of oil or varnish compositions. x i

. I include within the scope of this-invention sand-paper whether made with a backing of paper or any other conventional backing. material of the sand-paper art as well as articles made from the sand-paper of my invention. I. further include within the scope coated on one or both sides of the fabric the fabric of this invention sand-paper whether.

on that sidewhich bearsthe abrasive material. F v I The present application is a divisional application of applicants case, Serial No; 693,903, filed February 19, 1924.

I claim: I a

1. As a new article ofmanufacture a sandpaper product comprising a fabric base and abrasive material adhesively associated with said base by waterproof cellulosic coating material, said coating material containing afiller and also an emollient to maintain flexibility in the filler and the associated cellulosic material. p

' 2. As a new article of manufacture. a sand paper product comprising a fabric base, abrasive material adhesively associated with said base, and a waterproofcoating of cellulosic material, resin and oil, in, which thecellulosic material maintains the position'of the abrasive grains on the base, the resin serving as a filler and the oil as an emollient to maintain flexibility.

In testimony where my hand.

f I have hereunto set FRANK JOSEPH oBUP- 

